/* Resolve the IP address of local machine */
PJ_DEF(pj_status_t) pj_gethostip(int af, pj_sockaddr *addr)
{
unsigned i, count, cand_cnt;
enum {
CAND_CNT = 8,
/* Weighting to be applied to found addresses */
WEIGHT_HOSTNAME = 1, /* hostname IP is not always valid! */
WEIGHT_DEF_ROUTE = 2,
WEIGHT_INTERFACE = 1,
WEIGHT_LOOPBACK = -5,
WEIGHT_LINK_LOCAL = -4,
WEIGHT_DISABLED = -50,
MIN_WEIGHT = WEIGHT_DISABLED+1 /* minimum weight to use */
};
/* candidates: */
pj_sockaddr cand_addr[CAND_CNT];
int cand_weight[CAND_CNT];
int selected_cand;
char strip[PJ_INET6_ADDRSTRLEN+10];
/* Special IPv4 addresses. */
struct spec_ipv4_t
{
pj_uint32_t addr;
pj_uint32_t mask;
int weight;
} spec_ipv4[] =
{
/* 127.0.0.0/8, loopback addr will be used if there is no other
* addresses.
*/
{ 0x7f000000, 0xFF000000, WEIGHT_LOOPBACK },
/* 0.0.0.0/8, special IP that doesn't seem to be practically useful */
{ 0x00000000, 0xFF000000, WEIGHT_DISABLED },
/* 169.254.0.0/16, a zeroconf/link-local address, which has higher
* priority than loopback and will be used if there is no other
* valid addresses.
*/
{ 0xa9fe0000, 0xFFFF0000, WEIGHT_LINK_LOCAL }
};
/* Special IPv6 addresses */
struct spec_ipv6_t
{
pj_uint8_t addr[16];
pj_uint8_t mask[16];
int weight;
} spec_ipv6[] =
{
/* Loopback address, ::1/128 */
{ {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1},
{0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff},
WEIGHT_LOOPBACK
},
/* Link local, fe80::/10 */
{ {0xfe,0x80,0,0,0,0,0,0,0,0,0,0,0,0,0,0},
{0xff,0xc0,0,0,0,0,0,0,0,0,0,0,0,0,0,0},
WEIGHT_LINK_LOCAL
},
/* Disabled, ::/128 */
{ {0x0,0x0,0,0,0,0,0,0,0,0,0,0,0,0,0,0},
{ 0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff},
WEIGHT_DISABLED
}
};
pj_addrinfo ai;
pj_status_t status;
/* May not be used if TRACE_ is disabled */
PJ_UNUSED_ARG(strip);
#ifdef _MSC_VER
/* Get rid of "uninitialized he variable" with MS compilers */
pj_bzero(&ai, sizeof(ai));
#endif
cand_cnt = 0;
pj_bzero(cand_addr, sizeof(cand_addr));
pj_bzero(cand_weight, sizeof(cand_weight));
for (i=0; i<PJ_ARRAY_SIZE(cand_addr); ++i) {
cand_addr[i].addr.sa_family = (pj_uint16_t)af;
PJ_SOCKADDR_RESET_LEN(&cand_addr[i]);
}
addr->addr.sa_family = (pj_uint16_t)af;
PJ_SOCKADDR_RESET_LEN(addr);
#if !defined(PJ_GETHOSTIP_DISABLE_LOCAL_RESOLUTION) || \
PJ_GETHOSTIP_DISABLE_LOCAL_RESOLUTION == 0
TRACE_((THIS_FILE, "pj_gethostip() pj_getaddrinfo1"));
/* Get hostname's IP address */
count = 1;
status = pj_getaddrinfo(af, pj_gethostname(), &count, &ai);
if (status == PJ_SUCCESS) {
pj_assert(ai.ai_addr.addr.sa_family == (pj_uint16_t)af);
pj_sockaddr_copy_addr(&cand_addr[cand_cnt], &ai.ai_addr);
pj_sockaddr_set_port(&cand_addr[cand_cnt], 0);
cand_weight[cand_cnt] += WEIGHT_HOSTNAME;
++cand_cnt;
TRACE_((THIS_FILE, "hostname IP is %s",
pj_sockaddr_print(&ai.ai_addr, strip, sizeof(strip), 0)));
}
TRACE_((THIS_FILE, "pj_gethostip() pj_getaddrinfo2"));
#else
PJ_UNUSED_ARG(ai);
PJ_UNUSED_ARG(count);
#endif
/* Get default interface (interface for default route) */
if (cand_cnt < PJ_ARRAY_SIZE(cand_addr)) {
status = pj_getdefaultipinterface(af, addr);
if (status == PJ_SUCCESS) {
TRACE_((THIS_FILE, "default IP is %s",
pj_sockaddr_print(addr, strip, sizeof(strip), 0)));
pj_sockaddr_set_port(addr, 0);
for (i=0; i<cand_cnt; ++i) {
if (pj_sockaddr_cmp(&cand_addr[i], addr)==0)
break;
}
cand_weight[i] += WEIGHT_DEF_ROUTE;
if (i >= cand_cnt) {
pj_sockaddr_copy_addr(&cand_addr[i], addr);
++cand_cnt;
}
}
}
/* Enumerate IP interfaces */
if (cand_cnt < PJ_ARRAY_SIZE(cand_addr)) {
unsigned start_if = cand_cnt;
unsigned count = PJ_ARRAY_SIZE(cand_addr) - start_if;
status = pj_enum_ip_interface(af, &count, &cand_addr[start_if]);
if (status == PJ_SUCCESS && count) {
/* Clear the port number */
for (i=0; i<count; ++i)
pj_sockaddr_set_port(&cand_addr[start_if+i], 0);
/* For each candidate that we found so far (that is the hostname
* address and default interface address, check if they're found
* in the interface list. If found, add the weight, and if not,
* decrease the weight.
*/
for (i=0; i<cand_cnt; ++i) {
unsigned j;
for (j=0; j<count; ++j) {
if (pj_sockaddr_cmp(&cand_addr[i],
&cand_addr[start_if+j])==0)
break;
}
if (j == count) {
/* Not found */
cand_weight[i] -= WEIGHT_INTERFACE;
} else {
cand_weight[i] += WEIGHT_INTERFACE;
}
}
/* Add remaining interface to candidate list. */
for (i=0; i<count; ++i) {
unsigned j;
for (j=0; j<cand_cnt; ++j) {
if (pj_sockaddr_cmp(&cand_addr[start_if+i],
&cand_addr[j])==0)
break;
}
if (j == cand_cnt) {
pj_sockaddr_copy_addr(&cand_addr[cand_cnt],
&cand_addr[start_if+i]);
cand_weight[cand_cnt] += WEIGHT_INTERFACE;
++cand_cnt;
}
}
}
}
/* Apply weight adjustment for special IPv4/IPv6 addresses
* See http://trac.pjsip.org/repos/ticket/1046
*/
if (af == PJ_AF_INET) {
for (i=0; i<cand_cnt; ++i) {
unsigned j;
for (j=0; j<PJ_ARRAY_SIZE(spec_ipv4); ++j) {
pj_uint32_t a = pj_ntohl(cand_addr[i].ipv4.sin_addr.s_addr);
pj_uint32_t pa = spec_ipv4[j].addr;
pj_uint32_t pm = spec_ipv4[j].mask;
if ((a & pm) == pa) {
cand_weight[i] += spec_ipv4[j].weight;
break;
}
}
}
} else if (af == PJ_AF_INET6) {
for (i=0; i<PJ_ARRAY_SIZE(spec_ipv6); ++i) {
unsigned j;
for (j=0; j<cand_cnt; ++j) {
pj_uint8_t *a = cand_addr[j].ipv6.sin6_addr.s6_addr;
pj_uint8_t am[16];
pj_uint8_t *pa = spec_ipv6[i].addr;
pj_uint8_t *pm = spec_ipv6[i].mask;
unsigned k;
for (k=0; k<16; ++k) {
am[k] = (pj_uint8_t)((a[k] & pm[k]) & 0xFF);
}
if (pj_memcmp(am, pa, 16)==0) {
cand_weight[j] += spec_ipv6[i].weight;
}
}
}
} else {
return PJ_EAFNOTSUP;
}
/* Enumerate candidates to get the best IP address to choose */
selected_cand = -1;
for (i=0; i<cand_cnt; ++i) {
TRACE_((THIS_FILE, "Checking candidate IP %s, weight=%d",
pj_sockaddr_print(&cand_addr[i], strip, sizeof(strip), 0),
cand_weight[i]));
if (cand_weight[i] < MIN_WEIGHT) {
continue;
}
if (selected_cand == -1)
selected_cand = i;
else if (cand_weight[i] > cand_weight[selected_cand])
selected_cand = i;
}
/* If else fails, returns loopback interface as the last resort */
if (selected_cand == -1) {
if (af==PJ_AF_INET) {
addr->ipv4.sin_addr.s_addr = pj_htonl (0x7f000001);
} else {
pj_in6_addr *s6_addr;
s6_addr = (pj_in6_addr*) pj_sockaddr_get_addr(addr);
pj_bzero(s6_addr, sizeof(pj_in6_addr));
s6_addr->s6_addr[15] = 1;
}
TRACE_((THIS_FILE, "Loopback IP %s returned",
pj_sockaddr_print(addr, strip, sizeof(strip), 0)));
} else {
pj_sockaddr_copy_addr(addr, &cand_addr[selected_cand]);
TRACE_((THIS_FILE, "Candidate %s selected",
pj_sockaddr_print(addr, strip, sizeof(strip), 0)));
}
return PJ_SUCCESS;
}
static int purity_test(void)
{
PJ_LOG(3,("test", "...purity_test()"));
#if defined(PJ_SOCKADDR_HAS_LEN) && PJ_SOCKADDR_HAS_LEN!=0
/* Check on "sin_len" member of sockaddr */
{
const pj_str_t str_ip = {"1.1.1.1", 7};
pj_sockaddr addr[16];
pj_addrinfo ai[16];
unsigned cnt;
pj_status_t rc;
/* pj_enum_ip_interface() */
cnt = PJ_ARRAY_SIZE(addr);
rc = pj_enum_ip_interface(pj_AF_UNSPEC(), &cnt, addr);
if (rc == PJ_SUCCESS) {
while (cnt--)
CHECK_SA_ZERO_LEN(&addr[cnt], -10);
}
/* pj_gethostip() on IPv4 */
rc = pj_gethostip(pj_AF_INET(), &addr[0]);
if (rc == PJ_SUCCESS)
CHECK_SA_ZERO_LEN(&addr[0], -20);
/* pj_gethostip() on IPv6 */
rc = pj_gethostip(pj_AF_INET6(), &addr[0]);
if (rc == PJ_SUCCESS)
CHECK_SA_ZERO_LEN(&addr[0], -30);
/* pj_getdefaultipinterface() on IPv4 */
rc = pj_getdefaultipinterface(pj_AF_INET(), &addr[0]);
if (rc == PJ_SUCCESS)
CHECK_SA_ZERO_LEN(&addr[0], -40);
/* pj_getdefaultipinterface() on IPv6 */
rc = pj_getdefaultipinterface(pj_AF_INET6(), &addr[0]);
if (rc == PJ_SUCCESS)
CHECK_SA_ZERO_LEN(&addr[0], -50);
/* pj_getaddrinfo() on a host name */
cnt = PJ_ARRAY_SIZE(ai);
rc = pj_getaddrinfo(pj_AF_UNSPEC(), pj_gethostname(), &cnt, ai);
if (rc == PJ_SUCCESS) {
while (cnt--)
CHECK_SA_ZERO_LEN(&ai[cnt].ai_addr, -60);
}
/* pj_getaddrinfo() on an IP address */
cnt = PJ_ARRAY_SIZE(ai);
rc = pj_getaddrinfo(pj_AF_UNSPEC(), &str_ip, &cnt, ai);
if (rc == PJ_SUCCESS) {
pj_assert(cnt == 1);
CHECK_SA_ZERO_LEN(&ai[0].ai_addr, -70);
}
}
#endif
return 0;
}
